#!/usr/bin/perl6

use v6;

role Bird {
	has $!speed = 100;

	method get-speed() {return $!speed;}

	method fly($balance) {...}

	method walk() {
		say " walk ...."
	}
}

role Penguin does Bird{
	method fly($balance){
		say "Sorry, I can't fly ...";
	}
}

my $little = Penguin.new;

$little.walk();
$little.fly(120);
say $little.get-speed();